code: def test_time(self):
      dataset = Dataset(
          data=self.datalist * 2, transform=self.transform
      )  # contains data for 2 batches
      dataloader = DataLoader(
          dataset=dataset, batch_size=2, num_workers=0
      )
  
      tbuffer = ThreadBuffer(dataloader)
  
      with PerfContext() as pc:
          for _ in dataloader:
              time.sleep(
                  0.5
              )  # each batch takes 0.8 s to generate on top of this time
  
      unbuffered_time = pc.total_time
  
      with PerfContext() as pc:
          for _ in tbuffer:
              time.sleep(
                  0.5
              )  # while "computation" is happening the next batch is being generated, saving 0.4 s
  
      buffered_time = pc.total_time
      if sys.platform == "darwin":  # skip macOS measure
          print(
              f"darwin: Buffered time {buffered_time} vs unbuffered time {unbuffered_time}"
          )
      else:
          self.assertTrue(
              buffered_time < unbuffered_time,
              f"Buffered time {buffered_time} should be less than unbuffered time {unbuffered_time}",
          )
  
file_path: MONAI/tests/test_thread_buffer.py
imports: from __future__ import annotations
  import sys
  import time
  import unittest
  import torch
  from monai.data import DataLoader, Dataset, ThreadBuffer, ThreadDataLoader
  from monai.transforms import Compose, SimulateDelayd
  from monai.utils import PerfContext, set_determinism
  from tests.utils import assert_allclose
label_desc: Use image node_id 5 for calling the TestDataLoader obj's underlying member method code with example usage: obj.test_time() without return types